Tea tree oil is a natural essential oil from a tree of the class Myrtenceae, especially of Melaleuca. Tea tree oil has been used as a broad spectrum topical antiseptic for more than 70 years. In recent times, the anecdotal evidence as to the antimicrobial efficacy of tea tree oils has been substantiated by scientific evidence. Such evidence can be found in the work of Carson, C. F. and Riley, T. V, Antimicrobial activity of the Major Components of the essential oil of Melaleuca Alternifolia, Journal Applied Bacteriology, 78, 264-269 (1995); C. F. Carson, B. D. Cookson, H. D. Farrelly and T. V Riley, Susceptibility of methicillin-resistant Staphylococcus aureaus to the essential oil of Melaleuca Alternifolia, Journal Antimicrobial Chemotherapy, 35, 421-424 (1995); and Carson, C. F., Hammer, K. A. and Reiley, T. V. (1996) In vitro activity of the essential oil of Melaleuca Alternifolia against Streptococcus spp. Journal of Antimicrobial Chemotherapy 37: 1177-1178.
It is well recognised that commercial, industrial and hospital air conditioning ducting can be a major source of infection and re-infection in public and private buildings. The World Health Organisation (WHO) reported its findings on this subject in 1988. This report in brief stated that biological air contaminants in indoor air have been associated with half of all absenteeism and reduced worker efficiency discovered in the report.
International publication No. WO 88/10122 (Commonwealth Industrial Gases Ltd) describes the use of a biocidal composition comprising an oil of Melaleuca in disinfecting air conditioning systems. This procedure involves solubilising the tea tree oil in both ethanol and carbon dioxide and delivering the solubilised tea tree oil by gaseous carbon dioxide into air conditioning ducting. The procedure therefore requires a constant supply of carbon dioxide by way of carbon dioxide gas cylinders. Specialised equipment such as a high pressure rated gun, hoses and other automatic delivery apparatus are also required. In addition to the fact that this procedure requires specialised equipment and highly trained personal, the possible hazards associated with the use of carbon dioxide in these procedures are well documented. A safer and more cost effective procedure for disinfecting air conditioning systems is therefore desirable.
The positive effects of dispersing pleasant aromatic essential oil odours into public building air space are now well described in the medical literature. The traditional manner for achieving this is by the use of either electric diffusers or by candle warmed water or oil dispersed essential oil burners.
At the Plane Tree Public Hospital in California patients are given a choice of fragrances. In the St Croix Valley Memorial Hospital, Wisconsin, natural fragrances are used to counteract unpleasant odours and to generally improve the atmosphere of all patient care and amenity rooms. The Sloane Kettering Institute in New York has reported that the use of Heliotropin, a vanilla like perfume, has significantly reduced stress in cancer patients. Lavender and Camomile essential oils are now in regular use in hospitals in the United Kingdom. Where elderly patients have demonstrated a tendency to insomnia the use of lavender has been found to lead to less restlessness and an actual increase in the number of hours sleep.
At the Japan School of Medicine the worker Sagano has reported that the use of natural fragrance will help both in the relaxation of staff and patients. International Airlines as Virgin Airlines and New Zealand Airlines are using pure essential oils to assist customers overcome travel fatigue and jet lag. International Hotel Groups as the Marriott Chain use essential oil odours in the lobby areas of many of their hotels.
In all of the examples cited above traditional methods of dispersing the natural essential oil odours are employed. It is desirable to develop a method of dispersing essential oils which eliminates the need for electrical or candle or other such diffusers.